Bioaccumulation of Toxic Organic Compounds and Their Isomers into the Organism of Seals in West-Estonian Archipelago Biosphere Reserve

The Estonian coastal waters serve as the south-eastern boundary of the regular distribution of the grey (Halichoerus grypus and ringed Phoca hispida) seal in the Baltic Sea. During the annual molt period in May–June (in the Estonian coastal waters), the stock size is estimated to be 1200–1500 grey seal individuals – that is, roughly 25% of the whole Baltic population. If we compare the chlororganic contents of seals in different areas the Baltic Sea, we can see that the northern part of the Gulf of Riga and Väinameri Sea is the reference area of the Baltic Sea.     

轴装式转碟曝气机的研制

针对转碟曝气机在使用过程中出现的问题,进行重新设计,改善受力状况和工作条件,提高设备运行的可靠性,减少维护工作量,降低维护的难度和费用。     

仿生凹坑非光滑密封圈有限元分析

针对超临界流体萃取过程中高压环境下的密封问题,设计了一种具有仿生凹坑特征的新型密封圈。将仿生学原理应用到橡胶圈密封技术中,通过软件对光滑与非光滑表面密封圈进行数值模拟,观察在不同压缩量、不同凹坑直径和间距时,密封圈的接触应力和Von-Mises等效应力变化情况。计算结果表明,当压缩率为12%时,光滑和非光滑密封圈产生的接触应力均达到了超临界萃取过程工作的介质压力8 MPa,其中凹坑直径为2.0 mm、凹坑间距为3.0 mm的模型具有最好的密封性能和耐磨性。     

微生物絮凝剂产絮菌的分离与筛选

根据北方气温的变化特点,用活性污泥生物膜分离、筛选出DG1、DN1、H8、H13菌株,在低温条件下培养絮凝率分别达到87.35%、81.33%、83.79%、78.44%,为今后开展低温污水处理及絮凝机理的研究打下了基础。     

浮顶储罐二次密封油气空间放电分析

为避免浮顶储罐在遭受雷击时由于导电片设施在二次密封油气空间中放电引起密封圈火灾,在实验室建立了2 m直径油罐模型,开展导电片火花放电起始电流试验、导电片与罐壁形成空气间隙击穿放电初始电压试验,系统研究导电片在二次密封油气空间中的放电危险性。试验结果表明:导电片靠自身弹性与罐壁贴合时,雷电流大约在400 A时导电片开始产生点燃性火花放电;如导电片与罐壁贴合不良形成空气间隙,雷击情况下雷电流泄放瞬时浮顶与罐壁之间的电位差足以使一定大小的间隙击穿放电,当间隙大小为20~30 mm时,放电电压为26~40 kV。因此,储罐在遭受雷击时,导电片火花放电现象不可避免。结合储罐的实际运行情况,提出取消二次密封导电片、液下刮蜡器与浮顶进行可靠电气连接的改进措施,避免导电片在二次密封油气空间中放电发生,大大降低浮顶储罐雷击火灾事故。     

窗用材料与建筑节能

门窗对建筑耗能的影响,近年已引起人们的关注,为了寻求窗用材料与建筑节能的对应关系,对各种窗用材料与节能的关系进行了理论分析,并对其关系进行了较详细的讨论.探讨其节能规律,以其为节能窗的设计提供一些可靠依据.     

温度-湿度-高度环境对航天火工装置性能的影响

目的 研究温度-湿度-高度环境对航天火工装置密封性能的影响机理.方法 调研"温度-湿度-高度"环境的由来,对比不同标准中试验方法的差异,分析其作用过程,并分析两起因温度-湿度-高度环境导致的火工装置失效案例的故障原因及机理.结果 由于低温、低压与高温、高湿多次相互转化的过程,装置表面的冷凝水因"负压"特性被"压"入装置...     

某O型密封圈的双参数加速退化规律分析

目的研究某O型密封圈在温度影响下的退化规律。方法以压缩永久变形率和压缩应力松弛率作为参数,在50、60、70、80℃对某O型密封圈进行恒定应力加速退化试验,根据退化数据建立退化轨迹模型,确定伪失效寿命的分布,结合阿伦尼斯模型外推20℃时某O型密封圈的寿命,并进行可靠性分析。结果某O型密封圈的性能退化过程具有可加速性,它的伪失效寿命服从正态分布。根据压缩永久变形参数外推20℃下、0.9可靠度时,某O型圈的寿命为8.695年,根据压缩应力松弛参数外推的寿命为8.748年,根据双参数不相关的情况外推的寿命为8.655年,3次评估结果较为接近。结论文中使用的试验方法和数据处理方法能有效地评估某O型密封圈的寿命。考虑两个参数不相关情况时,得到的评估结果会小于单参数情况下的评估结果。     

Screening of the marine actinomycetes with anti-complement activity and isolation of the active fractions北大核心CSCD

Studies on anti-complement agents are essential for the development of drugs to treat various diseases caused by excessive or abnormal activation of the complement system. However, studies on microbial-derived anti-complement agents are still very limited. The anti-complement activities of 42 marine-derived actinomycete strains isolated from the sediment samples collected from Xinghai Bay in Dalian were studied using the hemolysis method. In addition, the active fractions of the strain Streptomyces sp. DUT11 were separated by C18 and Sephadex LH-20 column chromatography, and the active compounds with anti-complement activity were identified. Streptomyces strains S187, M5, S088, M8, S063, DUT11 and MD16 showed good anti-complement activities upon being cultured in TSB medium, with the strain DUT11 showing the best anti-complement activity among these strains. When different fermentation media were tested, the highest anti-complement activity of DUT11 was observed in M33 fermentation medium. The anti-complement activity was 56.5% for the extract of supernatant and 60.8% for the extract of mycelia, respectively. Furthermore, three compounds with anti-complement activity were obtained from the active components, which were identified as 3-indolecarboxylic acid (1), p-hydroxy benzoic acid (2) and 2-pyrrolecarboxylic acid (3). These results demonstrated that marine-derived streptomycetes can be employed to produce active compounds with anti-complement activity. This study presents a new alternative for the utilization of marine actinomycetes and provides a basis for the exploration of new anti-complement agents. © 2018 Science Press. All rights reserved.